refactor: standardize Dart and Android config across all 54 apps

- Bump all apps to sdk >=3.0.0 <4.0.0 and add flutter_lints + a shared
  analysis_options.yaml to every app (flutter analyze is now green repo-wide)
- Fix real compile errors in firebase_google_authentication and image_editor,
  plus deprecated APIs (Matrix4, SvgPicture.color, textScaleFactor),
  missing async 'mounted' guards, and misc lints via dart fix + manual fixes
- Align pubspec 'name' with each folder and Android namespace/applicationId
  with the documented github.nisrulz.* convention
- Convert bmi_calculator from a legacy Flutter module to a standard app
  with a proper android/ scaffold; fix missing android:exported in launcher
  manifests across 22 apps so all Android builds pass
- Untrack generated build files (GeneratedPluginRegistrant,
  .flutter-plugins-dependencies) and ignore them

lunch_app/analysis_options.yaml

@@ -0,0 +1,23 @@
+# Lint rules for Flutter apps.
+# See https://dart.dev/guides/language/analysis-options
+include: package:flutter_lints/flutter.yaml
+
+analyzer:
+  exclude:
+    - build/**
+    - android/**
+    - ios/**
+    - web/**
+    - windows/**
+    - macos/**
+    - linux/**
+
+linter:
+  rules:
+    # Noise in small sample apps; keep the code readable.
+    avoid_print: false
+    avoid_unnecessary_containers: false
+    file_names: false
+    library_private_types_in_public_api: false
+    non_constant_identifier_names: false
+    strict_top_level_inference: false

lunch_app/android/app/build.gradle.kts

@@ -6,7 +6,7 @@ plugins {
 }
 
 android {
-    namespace = "studio.sdev.lunch_app"
+    namespace = "github.nisrulz.lunch_app"
     compileSdk = flutter.compileSdkVersion
     ndkVersion = flutter.ndkVersion
 
@@ -16,7 +16,7 @@ android {
     }
 
     defaultConfig {
-        applicationId = "studio.sdev.lunch_app"
+        applicationId = "github.nisrulz.lunch_app"
         minSdk = flutter.minSdkVersion
         targetSdk = flutter.targetSdkVersion
         versionCode = flutter.versionCode

lunch_app/android/app/src/debug/AndroidManifest.xml

@@ -1,5 +1,4 @@
-<manifest xmlns:android="http://schemas.android.com/apk/res/android"
-    package="studio.sdev.lunch_app">
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
     <!-- Flutter needs it to communicate with the running application
          to allow setting breakpoints, to provide hot reload, etc.
     -->

lunch_app/android/app/src/main/AndroidManifest.xml

@@ -5,6 +5,7 @@
         android:icon="@mipmap/ic_launcher">
         <activity
             android:name="io.flutter.embedding.android.FlutterActivity"
+            android:exported="true"
             android:launchMode="singleTop"
             android:theme="@style/LaunchTheme"
             android:configChanges="orientation|keyboardHidden|keyboard|screenSize|smallestScreenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"

lunch_app/android/app/src/profile/AndroidManifest.xml

@@ -1,5 +1,4 @@
-<manifest xmlns:android="http://schemas.android.com/apk/res/android"
-    package="studio.sdev.lunch_app">
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
     <!-- Flutter needs it to communicate with the running application
          to allow setting breakpoints, to provide hot reload, etc.
     -->

lunch_app/lib/main.dart

@@ -1,11 +1,12 @@
 import 'package:flutter/material.dart';
-import 'package:lunch_app/views/prototype/food_detail_view.dart';
 
 import 'views/prototype/home.dart';
 
 void main() => runApp(LunchApp());
 
 class LunchApp extends StatelessWidget {
+  const LunchApp({super.key});
+
   @override
   Widget build(BuildContext context) {
     return MaterialApp(

lunch_app/lib/views/prototype/bottom_nav/bottom_nav.dart

@@ -1,6 +1,8 @@
 import 'package:flutter/material.dart';
 
 class BottomNav extends StatelessWidget {
+  const BottomNav({super.key});
+
   @override
   Widget build(BuildContext context) {
     return Container(
@@ -41,7 +43,7 @@ class BottomNav extends StatelessWidget {
                 Expanded(
                   child: Icon(
                     Icons.shopping_basket,
-                    color: Colors.white.withOpacity(0.5),
+                    color: Colors.white.withValues(alpha: 0.5),
                   ),
                 ),
               ],

lunch_app/lib/views/prototype/food_detail_view.dart

@@ -1,9 +1,10 @@
-import 'dart:ui';
 
 import 'package:flutter/material.dart';
 import 'package:lunch_app/views/prototype/widgets/carousel_indicator.dart';
 
 class FoodDetailView extends StatefulWidget {
+  const FoodDetailView({super.key});
+
   @override
   _FoodDetailViewState createState() => _FoodDetailViewState();
 }

lunch_app/lib/views/prototype/home.dart

@@ -7,6 +7,8 @@ import 'package:lunch_app/views/prototype/widgets/options_selector.dart';
 import 'bottom_nav/bottom_nav.dart';
 
 class Home extends StatefulWidget {
+  const Home({super.key});
+
   @override
   _HomeState createState() => _HomeState();
 }
@@ -21,7 +23,10 @@ class _HomeState extends State<Home> {
           child: SvgPicture.asset(
             "assets/nav/drawer.svg",
             width: 25,
-            color: Colors.black.withOpacity(0.7),
+            colorFilter: ColorFilter.mode(
+              Colors.black.withValues(alpha: 0.7),
+              BlendMode.srcIn,
+            ),
           ),
         ),
       ),

lunch_app/lib/views/prototype/widgets/carousel_indicator.dart

@@ -21,7 +21,7 @@ class CarouselIndicator extends StatelessWidget {
               height: 8,
               width: 8,
               decoration: BoxDecoration(
-                color: active ? Colors.white : Colors.white.withOpacity(0.4),
+                color: active ? Colors.white : Colors.white.withValues(alpha: 0.4),
                 shape: BoxShape.circle,
               ),
               margin: const EdgeInsets.only(right: 5),

lunch_app/lib/views/prototype/widgets/food_lister.dart

@@ -2,6 +2,8 @@ import 'package:flutter/material.dart';
 import 'package:lunch_app/views/prototype/food_detail_view.dart';
 
 class FoodLister extends StatefulWidget {
+  const FoodLister({super.key});
+
   @override
   _FoodListerState createState() => _FoodListerState();
 }
@@ -12,7 +14,7 @@ class _FoodListerState extends State<FoodLister> {
 
   @override
   Widget build(BuildContext context) {
-    return Container(
+    return SizedBox(
       height: MediaQuery.of(context).size.width * 0.8,
       child: PageView.builder(
         scrollDirection: Axis.horizontal,

lunch_app/pubspec.yaml

@@ -15,6 +15,7 @@ dependencies:
 dev_dependencies:
   flutter_test:
     sdk: flutter
+  flutter_lints: ^6.0.0
 
 flutter:
   uses-material-design: true